Deep eutectic solvents as green media for efficient extraction of terpene trilactones from Ginkgo biloba leaves

Deep eutectic solvents (DESs)-based ultrasonic extraction of terpene trilactones (TTLs) from Ginkgo biloba leaves was efficiently developed. Sixteen DESs were prepared, and DESs composed of choline chloride-urea (ChCl-U) and betaine-ethylene glycol (BE-EG) gave higher TTL extraction yields than the present, most efficient solvent 70% ethanol. The extraction conditions were further optimized, and the optimum conditions were as follows: taking BE-EG containing 40% (w/w) water as the extraction solvent, 1:10 of G. biloba leaves powder-to-solvent ratio, and ultrasonic treatment at 45 degrees C and 100W for 20min. A total extraction yield of 1.94 +/- 0.03mg/g was obtained under the optimum conditions, which indicated that 99.37% of TTLs could be extracted from the G. biloba leaves powder by a single extraction. Moreover, the polyamide resin was used to recover the TTLs in DES extracting solution, and recovery yield of 95.1% was attained. Therefore, BE-EG containing 40% (w/w) water was a potential alternative solvent for TTLs extraction from G. biloba leaves. [GRAPHICS]